CONCENTRATION OF RISK Accounts Receivable, Net of Allowance for Doubtful Accounts (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Concentration Risk [Line Items]
Allowance for Doubtful Accounts Receivable, Current	$ (1,261)	$ (1,026)
Accounts Receivable, Net, Current	94,085	64,880
Natural gas, NGLs and crude oil sales
Concentration Risk [Line Items]
Accounts Receivable, Gross	66,257	39,837
Joint interest billing
Concentration Risk [Line Items]
Accounts Receivable, Gross	20,558	6,896
Natural gas marketing
Concentration Risk [Line Items]
Accounts Receivable, Gross	6,210	8,209
Reimbursements for title defects
Concentration Risk [Line Items]
Accounts Receivable, Gross	0	7,579
Other Accounts Receivable
Concentration Risk [Line Items]
Accounts Receivable, Gross	$ 2,321	$ 3,385